Field of the Invention
The present invention relates generally to IR detectors and, more specifically, to IR detectors using a gas chromatographic in-column spectroscopy.
Description of the Prior Art
A significant remaining challenge today in the chem-bio defense community is the simultaneous and reliable detection of a large number of chemicals and types covering all the chemical warfare agents (CWAs) and toxic industrial chemicals (TICs) in a “point” detection application. The development of a detector with suitable analytical fidelity can be reduced to the development of strategies or techniques to best exploit differences in analyte physicochemical properties.
IR spectrophotometry is an established lab fixture providing rich molecular information content, however performance is degraded for complex mixtures and traditional hardware suffers from relatively low sensitivity.
Fan et al. have reported in-column sensing. U.S. Patent Application Publication 2013/0169970 by Fan et al. (Jul. 4, 2013) and Reddy et al., “Rapid, sensitive, and multiplexed on-chip optical sensors for micro-gas chromatography,” Lab Chip, 12, 901-05 (2012). However, Fan et al. perform non-spectroscopic sensing and focus on measuring refractive index changes in a sorbent coated sensor embedded in the gas chromatography (GC) column. This approach lacks the selectivity provided by an IR absorption spectroscopic sensing approach. Moreover, this approach uses discrete sensors that do not sense at all points along the column.